Submission #124980

#	Time	Username	Problem	Language	Result	Execution time	Memory
124980		kjp4155	Combo (IOI18_combo)	C++17	100 / 100	50 ms	568 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>

using namespace std;

string guess_sequence(int N) {
    char c = 'x';
    int t = press("AB");

    if( t >= 1 ){
        t = press("A");
        c = t ? 'A' : 'B';
    }
    else{
        t = press("X");
        c = t ? 'X' : 'Y';
    }

    vector<char> v = {'A', 'B', 'X', 'Y'};
    v.erase(find(v.begin(), v.end(), c));
    string ans = "";
    ans.push_back(c);

    if( ans.size() == N ) return ans;

    while( ans.size() < N-1 ){
        string query = "";
        query += ans; query += v[0]; query += v[0];
        query += ans; query += v[0]; query += v[1];
        query += ans; query += v[0]; query += v[2]; 
        query += ans; query += v[1];

        int t = press(query);
        if( t == ans.size() ) ans += v[2];
        else if( t == ans.size() + 1 ) ans += v[1];
        else if( t == ans.size() + 2 ) ans += v[0];
    }
    
    if( press(ans + v[0]) == N ) ans += v[0];
    else if( press(ans + v[1]) == N ) ans += v[1];
    else ans += v[2];

    return ans;
}

Compilation message (stderr)

combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:24:20: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   24 |     if( ans.size() == N ) return ans;
      |         ~~~~~~~~~~~^~~~
combo.cpp:26:23: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   26 |     while( ans.size() < N-1 ){
      |            ~~~~~~~~~~~^~~~~
combo.cpp:34:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |         if( t == ans.size() ) ans += v[2];
      |             ~~^~~~~~~~~~~~~
combo.cpp:35:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |         else if( t == ans.size() + 1 ) ans += v[1];
      |                  ~~^~~~~~~~~~~~~~~~~
combo.cpp:36:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |         else if( t == ans.size() + 2 ) ans += v[0];
      |                  ~~^~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 95 / 95